Options
Effect of europium(II) stearate on the mechanical properties and the oxidation resistance of UHMWPE
Publikationstyp
Journal Article
Date Issued
2010-11-21
Sprache
English
Institut
Volume
4
Issue
5
Start Page
821
End Page
826
Citation
Journal of the Mechanical Behavior of Biomedical Materials 4 (5): 821-826 (2011)
Publisher DOI
Scopus ID
PubMed ID
21565729
Publisher
Elsevier
The objective of this pilot study is to investigate the effect of europium(II) stearate additive on the mechanical properties and oxidation resistance of an ultra-high molecular weight polyethylene (UHMWPE), which has been used as an articulating surface in prosthetic devices for many years. It is hypothesized in this study that combining the UHMWPE with lanthanide stearates could enhance oxidation resistance, leading to better preservation of the material's mechanical integrity.Compression molded UHMWPE was doped at 0, 375 and 750 ppm of europium(II) stearate, γ-irradiated to 35 kGy in a nitrogen atmosphere, and accelerated aged in accordance with the ASTM standard F2003-02. Non-irradiated and nonaged samples were used as controls. Miniature samples were comparatively tested for mechanical properties using the small punch test. Oxidation indices (OIs) were obtained through the FTIR spectroscopy on thin film sections of all irradiated samples.The UHMWPE doped with the europium(II) stearate had the same small punch test curve shape as the conventional UHMWPE control; the ultimate displacement remained unchanged (approximately 4.33±0.02 mm), while the ultimate load and work-to-failure exhibited only small changes (<7.5% and <5.0%, respectively). The doped material was more resistant to oxidation than the control material, retaining 83% of its as-irradiated work-to-failure after irradiation and accelerated aging, versus only 53% for the control. Accelerated aging changed the average oxidation index of the control group from 0.07 to 0.40; whereas the average oxidation indices changed from 0.03 to 0.15 and from 0.05 to 0.13 for the 375 ppm and the 750 ppm doped condition, respectively.
Subjects
Europium
Lanthanide
Oxidation
Polyethylene
Small-punch-test
Stabilization
Stearate
UHMWPE
DDC Class
540: Chemie